The invention is applied industrially in the sector of pharmaceutical machines known as capping machines operating intermittently or continuously and designed to open, fill and close hard-gelatin capsules which are fed pre-closed to said machines. In particular, the invention refers to the devices which feed the capsules into the seats or sleeves of the capping machines. FIGS. 1 and 2 in the accompanying drawings show, with parts sectioned and in different operating conditions, a side elevation view of a known device for feeding the capsules to the sleeves of a capping machine. From the said figures it can be seen that the hard-gelatin capsules C are provided with a bottom cap or base C1 with a rounded end, onto which a covering cap or lid C2 with a rounded end is fitted. The external diameter of the base C1 is usually less than the external diameter of the lid C2. The empty and pre-closed capsules C are placed randomly inside a hopperxe2x80x94not shownxe2x80x94inside which a hollow and vertical tube 1 enters at the bottom and moves axially with an alternating movement, the internal diameter of said tube being slightly greater than the external diameter of the lid C2 of the capsules C such that the latter enter into the tube in succession, vertically arranged and randomly oriented. An intercepting element 2 is laterally hinged on the tube 1 at the pivot 3 and, via spring means (not shown), is normally kept in the active position for retaining the capsules C inside the tube 1 when the latter is raised as shown in FIG. 2 and which, when instead the same tube 1 is lowered as shown in FIG. 1, interferes with stopping means 4 and retracts so as to allow a capsule C to fall into a calibrated well 5 where the said capsule C remains in a vertical position resting on the bottom 105 of said well. The well 5 is located in the middle part of a horizontal, straight and flat channel 6, an end section 106 of which has a width slightly smaller than the external diameter of the lid C2 of the capsules C, while in the section at the opposite end of the same channel 6 there slides a horizontal thruster 7 provided on its face directed towards the well 5 with a tip 107 located about halfway up the height of this well 5. The thruster 7 is for example hinged at 10b, via a connecting rod 8, with an angled lever 9 which is pivotably mounted in between at 10 on a fixed support 11 and hinged at 10a with the slide 101 which supports the tube 1 and from which the said thruster 7 derives the movement which causes it to move to the right when the tube 1 is raised as shown in FIG. 2 and instead causes it to return into the rest position as can be seen in FIG. 1, when the said tube 1 is lowered. During operation of the apparatus, when the thruster 7 moves to the right, its tip 107 touches, in the middle part, the capsule C located inside the well 5 and pushes it into the section 106. If the capsule C is oriented with its base C1 upwards, the tip 107 and the friction of the channel section 106 against the lid C2 have the effect that the said capsule C follows the movement of the thruster 7, rotating in an anti-clockwise direction when viewing FIG. 1, until it reaches the position shown in continuous lines and indicated by Cxe2x80x2 in FIG. 2. If, on the other hand, the capsule C is oriented inside the well 5 with its lid C2 downwards, the said capsule C follows the movement of the thruster 7 and at the same time rotates in the clockwise direction when viewing FIG. 1 and reaches the position shown in broken lines and indicated by Cxe2x80x3 in FIG. 2. In either case, after the active stroke of the thruster 7, the capsule C reaches the end part of the section 106 of the channel 6, arranged substantially horizontally and with the lid C2 again directed to the left when viewing FIG. 2. From FIGS. 1 and 2 it can be seen that the tube 1 has, associated with it, a vertical thruster 12 with a tip 112 directed towards the middle part of the capsules in the positions Cxe2x80x2 or Cxe2x80x3, so that when the horizontal thruster 7 returns into the rest position after lowering of the tube 1, the vertical thruster 12 pushes the capsule C downwards and at the same time causes it to rotate clockwise when viewing FIG. 1, again owing to the friction exerted by the section 106 of the channel 6 on the lid C2 of the said capsule C, until the said capsule C mates with the rounded recess 212 in the thruster 12 and is arranged vertically with the lid C2 upwards and the base C1 downwards. In this condition the capsule is made to leave the bottom part of the section 106 of the channel 6 and fall into the sleeve 13 of one of the radial slides S of the capping machine carousel, the sleeve 13 being shaped so as to retain the capsule by means of the step formed by the edge of the lid C2.
At present, in the known devices of the type described above, owing to the relative movements which the capsules C undergo during storage, transportation and introduction into the said feeding hopper, and also owing to the alternating movement of the tube 1 inside said hopper, a capsule C may open and the well 5, instead of receiving a capsule C together with its associated lid C2 directed downwards or upwards, may receive only the base C1 of a capsule C or else a capsule C which below will be described by the term xe2x80x9cdefective capsulexe2x80x9d and which has two lids C2 on one end or on the opposite ends of a base C1. In such cases, the base or the defective capsule with the two lids C2 are transferred by the horizontal thruster 7 above the sleeve 13 so that only the base C1 is able to fall by means of gravity inside the sleeve 13, or the subsequent intervention of the vertical thruster 12 may insert the defective capsule C with the two lids C2 into the sleeve 13, consequently obstructing the said sleeve 13 and in certain cases causing blockage of the capping machine.
The invention intends to overcome the said drawback and limitation of the known art with the following proposed solution. Respective secondary thrusters are added to the horizontal and vertical thrusters or primary thrusters and the guide channel is provided with dimensions such that the capsule guiding and feeding steps are performed with minor successive displacements of the said capsule. For this purpose the primary vertical thruster is made to operate in a position distant from the capping machine sleeve, i.e. at a distance such as to allow discarding and removal of the defective capsules with a double base or the individual bases of the said capsules. The portion of the guide channel section inside which the secondary vertical thruster operates is provided with dimensions such that it has a width slightly less than that of the upstream portion of the said channel section in order to retain firmly the ends of any defective capsules which have lids on the opposite ends of a base. Such a defective capsule, arranged horizontally or inclined by the primary horizontal thruster, is then acted on both by the tip of the primary vertical thruster and by a front and rear face of the secondary vertical thruster able to expel this defective capsule from the bottom of the guide channel.